| 1 | NAME |
1 | NAME |
| 2 | IO::AIO - Asynchronous Input/Output |
2 | IO::AIO - Asynchronous/Advanced Input/Output |
| 3 | |
3 | |
| 4 | SYNOPSIS |
4 | SYNOPSIS |
| 5 | use IO::AIO; |
5 | use IO::AIO; |
| 6 | |
6 | |
| 7 | aio_open "/etc/passwd", IO::AIO::O_RDONLY, 0, sub { |
7 | aio_open "/etc/passwd", IO::AIO::O_RDONLY, 0, sub { |
| … | |
… | |
| 55 | not well-supported or restricted (GNU/Linux doesn't allow them on normal |
55 | not well-supported or restricted (GNU/Linux doesn't allow them on normal |
| 56 | files currently, for example), and they would only support aio_read and |
56 | files currently, for example), and they would only support aio_read and |
| 57 | aio_write, so the remaining functionality would have to be implemented |
57 | aio_write, so the remaining functionality would have to be implemented |
| 58 | using threads anyway. |
58 | using threads anyway. |
| 59 | |
59 | |
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60 | In addition to asynchronous I/O, this module also exports some rather |
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61 | arcane interfaces, such as "madvise" or linux's "splice" system call, |
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62 | which is why the "A" in "AIO" can also mean *advanced*. |
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63 | |
| 60 | Although the module will work in the presence of other (Perl-) threads, |
64 | Although the module will work in the presence of other (Perl-) threads, |
| 61 | it is currently not reentrant in any way, so use appropriate locking |
65 | it is currently not reentrant in any way, so use appropriate locking |
| 62 | yourself, always call "poll_cb" from within the same thread, or never |
66 | yourself, always call "poll_cb" from within the same thread, or never |
| 63 | call "poll_cb" (or other "aio_" functions) recursively. |
67 | call "poll_cb" (or other "aio_" functions) recursively. |
| 64 | |
68 | |
| 65 | EXAMPLE |
69 | EXAMPLE |
| 66 | This is a simple example that uses the EV module and loads /etc/passwd |
70 | This is a simple example that uses the EV module and loads /etc/passwd |
| 67 | asynchronously: |
71 | asynchronously: |
| 68 | |
72 | |
| 69 | use Fcntl; |
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| 70 | use EV; |
73 | use EV; |
| 71 | use IO::AIO; |
74 | use IO::AIO; |
| 72 | |
75 | |
| 73 | # register the IO::AIO callback with EV |
76 | # register the IO::AIO callback with EV |
| 74 | my $aio_w = EV::io IO::AIO::poll_fileno, EV::READ, \&IO::AIO::poll_cb; |
77 | my $aio_w = EV::io IO::AIO::poll_fileno, EV::READ, \&IO::AIO::poll_cb; |
| … | |
… | |
| 91 | |
94 | |
| 92 | # file contents now in $contents |
95 | # file contents now in $contents |
| 93 | print $contents; |
96 | print $contents; |
| 94 | |
97 | |
| 95 | # exit event loop and program |
98 | # exit event loop and program |
| 96 | EV::unloop; |
99 | EV::break; |
| 97 | }; |
100 | }; |
| 98 | }; |
101 | }; |
| 99 | |
102 | |
| 100 | # possibly queue up other requests, or open GUI windows, |
103 | # possibly queue up other requests, or open GUI windows, |
| 101 | # check for sockets etc. etc. |
104 | # check for sockets etc. etc. |
| 102 | |
105 | |
| 103 | # process events as long as there are some: |
106 | # process events as long as there are some: |
| 104 | EV::loop; |
107 | EV::run; |
| 105 | |
108 | |
| 106 | REQUEST ANATOMY AND LIFETIME |
109 | REQUEST ANATOMY AND LIFETIME |
| 107 | Every "aio_*" function creates a request. which is a C data structure |
110 | Every "aio_*" function creates a request. which is a C data structure |
| 108 | not directly visible to Perl. |
111 | not directly visible to Perl. |
| 109 | |
112 | |
| … | |
… | |
| 146 | the actual aio request is severed and calling its methods will |
149 | the actual aio request is severed and calling its methods will |
| 147 | either do nothing or result in a runtime error). |
150 | either do nothing or result in a runtime error). |
| 148 | |
151 | |
| 149 | FUNCTIONS |
152 | FUNCTIONS |
| 150 | QUICK OVERVIEW |
153 | QUICK OVERVIEW |
| 151 | This section simply lists the prototypes of the most important functions |
154 | This section simply lists the prototypes most of the functions for quick |
| 152 | for quick reference. See the following sections for function-by-function |
155 | reference. See the following sections for function-by-function |
| 153 | documentation. |
156 | documentation. |
| 154 | |
157 | |
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158 | aio_wd $pathname, $callback->($wd) |
| 155 | aio_open $pathname, $flags, $mode, $callback->($fh) |
159 | aio_open $pathname, $flags, $mode, $callback->($fh) |
| 156 | aio_close $fh, $callback->($status) |
160 | aio_close $fh, $callback->($status) |
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161 | aio_seek $fh,$offset,$whence, $callback->($offs) |
| 157 | aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval) |
162 | aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval) |
| 158 | aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval) |
163 | aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval) |
| 159 | aio_sendfile $out_fh, $in_fh, $in_offset, $length, $callback->($retval) |
164 | aio_sendfile $out_fh, $in_fh, $in_offset, $length, $callback->($retval) |
| 160 | aio_readahead $fh,$offset,$length, $callback->($retval) |
165 | aio_readahead $fh,$offset,$length, $callback->($retval) |
| 161 | aio_stat $fh_or_path, $callback->($status) |
166 | aio_stat $fh_or_path, $callback->($status) |
| 162 | aio_lstat $fh, $callback->($status) |
167 | aio_lstat $fh, $callback->($status) |
| 163 | aio_statvfs $fh_or_path, $callback->($statvfs) |
168 | aio_statvfs $fh_or_path, $callback->($statvfs) |
| 164 | aio_utime $fh_or_path, $atime, $mtime, $callback->($status) |
169 | aio_utime $fh_or_path, $atime, $mtime, $callback->($status) |
| 165 | aio_chown $fh_or_path, $uid, $gid, $callback->($status) |
170 | aio_chown $fh_or_path, $uid, $gid, $callback->($status) |
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171 | aio_chmod $fh_or_path, $mode, $callback->($status) |
| 166 | aio_truncate $fh_or_path, $offset, $callback->($status) |
172 | aio_truncate $fh_or_path, $offset, $callback->($status) |
| 167 | aio_chmod $fh_or_path, $mode, $callback->($status) |
173 | aio_allocate $fh, $mode, $offset, $len, $callback->($status) |
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174 | aio_fiemap $fh, $start, $length, $flags, $count, $cb->(\@extents) |
| 168 | aio_unlink $pathname, $callback->($status) |
175 | aio_unlink $pathname, $callback->($status) |
| 169 | aio_mknod $path, $mode, $dev, $callback->($status) |
176 | aio_mknod $pathname, $mode, $dev, $callback->($status) |
| 170 | aio_link $srcpath, $dstpath, $callback->($status) |
177 | aio_link $srcpath, $dstpath, $callback->($status) |
| 171 | aio_symlink $srcpath, $dstpath, $callback->($status) |
178 | aio_symlink $srcpath, $dstpath, $callback->($status) |
| 172 | aio_readlink $path, $callback->($link) |
179 | aio_readlink $pathname, $callback->($link) |
| 173 | aio_realpath $path, $callback->($link) |
180 | aio_realpath $pathname, $callback->($path) |
| 174 | aio_rename $srcpath, $dstpath, $callback->($status) |
181 | aio_rename $srcpath, $dstpath, $callback->($status) |
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182 | aio_rename2 $srcpath, $dstpath, $flags, $callback->($status) |
| 175 | aio_mkdir $pathname, $mode, $callback->($status) |
183 | aio_mkdir $pathname, $mode, $callback->($status) |
| 176 | aio_rmdir $pathname, $callback->($status) |
184 | aio_rmdir $pathname, $callback->($status) |
| 177 | aio_readdir $pathname, $callback->($entries) |
185 | aio_readdir $pathname, $callback->($entries) |
| 178 | aio_readdirx $pathname, $flags, $callback->($entries, $flags) |
186 | aio_readdirx $pathname, $flags, $callback->($entries, $flags) |
| 179 | IO::AIO::READDIR_DENTS IO::AIO::READDIR_DIRS_FIRST |
187 | IO::AIO::READDIR_DENTS IO::AIO::READDIR_DIRS_FIRST |
| 180 | IO::AIO::READDIR_STAT_ORDER IO::AIO::READDIR_FOUND_UNKNOWN |
188 | IO::AIO::READDIR_STAT_ORDER IO::AIO::READDIR_FOUND_UNKNOWN |
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189 | aio_scandir $pathname, $maxreq, $callback->($dirs, $nondirs) |
| 181 | aio_load $path, $data, $callback->($status) |
190 | aio_load $pathname, $data, $callback->($status) |
| 182 | aio_copy $srcpath, $dstpath, $callback->($status) |
191 | aio_copy $srcpath, $dstpath, $callback->($status) |
| 183 | aio_move $srcpath, $dstpath, $callback->($status) |
192 | aio_move $srcpath, $dstpath, $callback->($status) |
| 184 | aio_scandir $path, $maxreq, $callback->($dirs, $nondirs) |
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| 185 | aio_rmtree $path, $callback->($status) |
193 | aio_rmtree $pathname, $callback->($status) |
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194 | aio_fcntl $fh, $cmd, $arg, $callback->($status) |
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195 | aio_ioctl $fh, $request, $buf, $callback->($status) |
| 186 | aio_sync $callback->($status) |
196 | aio_sync $callback->($status) |
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197 | aio_syncfs $fh, $callback->($status) |
| 187 | aio_fsync $fh, $callback->($status) |
198 | aio_fsync $fh, $callback->($status) |
| 188 | aio_fdatasync $fh, $callback->($status) |
199 | aio_fdatasync $fh, $callback->($status) |
| 189 | aio_sync_file_range $fh, $offset, $nbytes, $flags, $callback->($status) |
200 | aio_sync_file_range $fh, $offset, $nbytes, $flags, $callback->($status) |
| 190 | aio_pathsync $path, $callback->($status) |
201 | aio_pathsync $pathname, $callback->($status) |
| 191 | aio_msync $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status) |
202 | aio_msync $scalar, $offset = 0, $length = undef, flags = MS_SYNC, $callback->($status) |
| 192 | aio_mtouch $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status) |
203 | aio_mtouch $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status) |
| 193 | aio_mlock $scalar, $offset = 0, $length = undef, $callback->($status) |
204 | aio_mlock $scalar, $offset = 0, $length = undef, $callback->($status) |
| 194 | aio_mlockall $flags, $callback->($status) |
205 | aio_mlockall $flags, $callback->($status) |
| 195 | aio_group $callback->(...) |
206 | aio_group $callback->(...) |
| 196 | aio_nop $callback->() |
207 | aio_nop $callback->() |
| … | |
… | |
| 210 | IO::AIO::idle_timeout $seconds |
221 | IO::AIO::idle_timeout $seconds |
| 211 | IO::AIO::max_outstanding $maxreqs |
222 | IO::AIO::max_outstanding $maxreqs |
| 212 | IO::AIO::nreqs |
223 | IO::AIO::nreqs |
| 213 | IO::AIO::nready |
224 | IO::AIO::nready |
| 214 | IO::AIO::npending |
225 | IO::AIO::npending |
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226 | $nfd = IO::AIO::get_fdlimit [EXPERIMENTAL] |
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227 | IO::AIO::min_fdlimit $nfd [EXPERIMENTAL] |
| 215 | |
228 | |
| 216 | IO::AIO::sendfile $ofh, $ifh, $offset, $count |
229 | IO::AIO::sendfile $ofh, $ifh, $offset, $count |
| 217 | IO::AIO::fadvise $fh, $offset, $len, $advice |
230 | IO::AIO::fadvise $fh, $offset, $len, $advice |
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231 | IO::AIO::mmap $scalar, $length, $prot, $flags[, $fh[, $offset]] |
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232 | IO::AIO::munmap $scalar |
| 218 | IO::AIO::madvise $scalar, $offset, $length, $advice |
233 | IO::AIO::madvise $scalar, $offset, $length, $advice |
| 219 | IO::AIO::mprotect $scalar, $offset, $length, $protect |
234 | IO::AIO::mprotect $scalar, $offset, $length, $protect |
| 220 | IO::AIO::munlock $scalar, $offset = 0, $length = undef |
235 | IO::AIO::munlock $scalar, $offset = 0, $length = undef |
| 221 | IO::AIO::munlockall |
236 | IO::AIO::munlockall |
| 222 | |
237 | |
| 223 | AIO REQUEST FUNCTIONS |
238 | API NOTES |
| 224 | All the "aio_*" calls are more or less thin wrappers around the syscall |
239 | All the "aio_*" calls are more or less thin wrappers around the syscall |
| 225 | with the same name (sans "aio_"). The arguments are similar or |
240 | with the same name (sans "aio_"). The arguments are similar or |
| 226 | identical, and they all accept an additional (and optional) $callback |
241 | identical, and they all accept an additional (and optional) $callback |
| 227 | argument which must be a code reference. This code reference will get |
242 | argument which must be a code reference. This code reference will be |
| 228 | called with the syscall return code (e.g. most syscalls return -1 on |
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| 229 | error, unlike perl, which usually delivers "false") as its sole argument |
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| 230 | after the given syscall has been executed asynchronously. |
243 | called after the syscall has been executed in an asynchronous fashion. |
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244 | The results of the request will be passed as arguments to the callback |
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245 | (and, if an error occured, in $!) - for most requests the syscall return |
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246 | code (e.g. most syscalls return -1 on error, unlike perl, which usually |
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247 | delivers "false"). |
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248 | |
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249 | Some requests (such as "aio_readdir") pass the actual results and |
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250 | communicate failures by passing "undef". |
| 231 | |
251 | |
| 232 | All functions expecting a filehandle keep a copy of the filehandle |
252 | All functions expecting a filehandle keep a copy of the filehandle |
| 233 | internally until the request has finished. |
253 | internally until the request has finished. |
| 234 | |
254 | |
| 235 | All functions return request objects of type IO::AIO::REQ that allow |
255 | All functions return request objects of type IO::AIO::REQ that allow |
| 236 | further manipulation of those requests while they are in-flight. |
256 | further manipulation of those requests while they are in-flight. |
| 237 | |
257 | |
| 238 | The pathnames you pass to these routines *must* be absolute and encoded |
258 | The pathnames you pass to these routines *should* be absolute. The |
| 239 | as octets. The reason for the former is that at the time the request is |
259 | reason for this is that at the time the request is being executed, the |
| 240 | being executed, the current working directory could have changed. |
260 | current working directory could have changed. Alternatively, you can |
| 241 | Alternatively, you can make sure that you never change the current |
261 | make sure that you never change the current working directory anywhere |
| 242 | working directory anywhere in the program and then use relative paths. |
262 | in the program and then use relative paths. You can also take advantage |
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263 | of IO::AIOs working directory abstraction, that lets you specify paths |
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264 | relative to some previously-opened "working directory object" - see the |
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265 | description of the "IO::AIO::WD" class later in this document. |
| 243 | |
266 | |
| 244 | To encode pathnames as octets, either make sure you either: a) always |
267 | To encode pathnames as octets, either make sure you either: a) always |
| 245 | pass in filenames you got from outside (command line, readdir etc.) |
268 | pass in filenames you got from outside (command line, readdir etc.) |
| 246 | without tinkering, b) are ASCII or ISO 8859-1, c) use the Encode module |
269 | without tinkering, b) are in your native filesystem encoding, c) use the |
| 247 | and encode your pathnames to the locale (or other) encoding in effect in |
270 | Encode module and encode your pathnames to the locale (or other) |
| 248 | the user environment, d) use Glib::filename_from_unicode on unicode |
271 | encoding in effect in the user environment, d) use |
| 249 | filenames or e) use something else to ensure your scalar has the correct |
272 | Glib::filename_from_unicode on unicode filenames or e) use something |
| 250 | contents. |
273 | else to ensure your scalar has the correct contents. |
| 251 | |
274 | |
| 252 | This works, btw. independent of the internal UTF-8 bit, which IO::AIO |
275 | This works, btw. independent of the internal UTF-8 bit, which IO::AIO |
| 253 | handles correctly whether it is set or not. |
276 | handles correctly whether it is set or not. |
| 254 | |
277 | |
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278 | AIO REQUEST FUNCTIONS |
| 255 | $prev_pri = aioreq_pri [$pri] |
279 | $prev_pri = aioreq_pri [$pri] |
| 256 | Returns the priority value that would be used for the next request |
280 | Returns the priority value that would be used for the next request |
| 257 | and, if $pri is given, sets the priority for the next aio request. |
281 | and, if $pri is given, sets the priority for the next aio request. |
| 258 | |
282 | |
| 259 | The default priority is 0, the minimum and maximum priorities are -4 |
283 | The default priority is 0, the minimum and maximum priorities are -4 |
| … | |
… | |
| 281 | Similar to "aioreq_pri", but subtracts the given value from the |
305 | Similar to "aioreq_pri", but subtracts the given value from the |
| 282 | current priority, so the effect is cumulative. |
306 | current priority, so the effect is cumulative. |
| 283 | |
307 | |
| 284 | aio_open $pathname, $flags, $mode, $callback->($fh) |
308 | aio_open $pathname, $flags, $mode, $callback->($fh) |
| 285 | Asynchronously open or create a file and call the callback with a |
309 | Asynchronously open or create a file and call the callback with a |
| 286 | newly created filehandle for the file. |
310 | newly created filehandle for the file (or "undef" in case of an |
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311 | error). |
| 287 | |
312 | |
| 288 | The pathname passed to "aio_open" must be absolute. See API NOTES, |
313 | The pathname passed to "aio_open" must be absolute. See API NOTES, |
| 289 | above, for an explanation. |
314 | above, for an explanation. |
| 290 | |
315 | |
| 291 | The $flags argument is a bitmask. See the "Fcntl" module for a list. |
316 | The $flags argument is a bitmask. See the "Fcntl" module for a list. |
| … | |
… | |
| 314 | "O_APPEND"), the following POSIX and non-POSIX constants are |
339 | "O_APPEND"), the following POSIX and non-POSIX constants are |
| 315 | available (missing ones on your system are, as usual, 0): |
340 | available (missing ones on your system are, as usual, 0): |
| 316 | |
341 | |
| 317 | "O_ASYNC", "O_DIRECT", "O_NOATIME", "O_CLOEXEC", "O_NOCTTY", |
342 | "O_ASYNC", "O_DIRECT", "O_NOATIME", "O_CLOEXEC", "O_NOCTTY", |
| 318 | "O_NOFOLLOW", "O_NONBLOCK", "O_EXEC", "O_SEARCH", "O_DIRECTORY", |
343 | "O_NOFOLLOW", "O_NONBLOCK", "O_EXEC", "O_SEARCH", "O_DIRECTORY", |
| 319 | "O_DSYNC", "O_RSYNC", "O_SYNC" and "O_TTY_INIT". |
344 | "O_DSYNC", "O_RSYNC", "O_SYNC", "O_PATH", "O_TMPFILE", and |
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345 | "O_TTY_INIT". |
| 320 | |
346 | |
| 321 | aio_close $fh, $callback->($status) |
347 | aio_close $fh, $callback->($status) |
| 322 | Asynchronously close a file and call the callback with the result |
348 | Asynchronously close a file and call the callback with the result |
| 323 | code. |
349 | code. |
| 324 | |
350 | |
| … | |
… | |
| 330 | will use dup2 to overwrite the file descriptor with the write-end of |
356 | will use dup2 to overwrite the file descriptor with the write-end of |
| 331 | a pipe (the pipe fd will be created on demand and will be cached). |
357 | a pipe (the pipe fd will be created on demand and will be cached). |
| 332 | |
358 | |
| 333 | Or in other words: the file descriptor will be closed, but it will |
359 | Or in other words: the file descriptor will be closed, but it will |
| 334 | not be free for reuse until the perl filehandle is closed. |
360 | not be free for reuse until the perl filehandle is closed. |
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361 | |
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362 | aio_seek $fh, $offset, $whence, $callback->($offs) |
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363 | Seeks the filehandle to the new $offset, similarly to perl's |
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364 | "sysseek". The $whence can use the traditional values (0 for |
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365 | "IO::AIO::SEEK_SET", 1 for "IO::AIO::SEEK_CUR" or 2 for |
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366 | "IO::AIO::SEEK_END"). |
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367 | |
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368 | The resulting absolute offset will be passed to the callback, or -1 |
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369 | in case of an error. |
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370 | |
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371 | In theory, the $whence constants could be different than the |
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372 | corresponding values from Fcntl, but perl guarantees they are the |
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373 | same, so don't panic. |
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374 | |
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375 | As a GNU/Linux (and maybe Solaris) extension, also the constants |
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376 | "IO::AIO::SEEK_DATA" and "IO::AIO::SEEK_HOLE" are available, if they |
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377 | could be found. No guarantees about suitability for use in |
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378 | "aio_seek" or Perl's "sysseek" can be made though, although I would |
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379 | naively assume they "just work". |
| 335 | |
380 | |
| 336 | aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval) |
381 | aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval) |
| 337 | aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval) |
382 | aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval) |
| 338 | Reads or writes $length bytes from or to the specified $fh and |
383 | Reads or writes $length bytes from or to the specified $fh and |
| 339 | $offset into the scalar given by $data and offset $dataoffset and |
384 | $offset into the scalar given by $data and offset $dataoffset and |
| 340 | calls the callback without the actual number of bytes read (or -1 on |
385 | calls the callback with the actual number of bytes transferred (or |
| 341 | error, just like the syscall). |
386 | -1 on error, just like the syscall). |
| 342 | |
387 | |
| 343 | "aio_read" will, like "sysread", shrink or grow the $data scalar to |
388 | "aio_read" will, like "sysread", shrink or grow the $data scalar to |
| 344 | offset plus the actual number of bytes read. |
389 | offset plus the actual number of bytes read. |
| 345 | |
390 | |
| 346 | If $offset is undefined, then the current file descriptor offset |
391 | If $offset is undefined, then the current file descriptor offset |
| … | |
… | |
| 403 | As native sendfile syscalls (as practically any non-POSIX interface |
448 | As native sendfile syscalls (as practically any non-POSIX interface |
| 404 | hacked together in a hurry to improve benchmark numbers) tend to be |
449 | hacked together in a hurry to improve benchmark numbers) tend to be |
| 405 | rather buggy on many systems, this implementation tries to work |
450 | rather buggy on many systems, this implementation tries to work |
| 406 | around some known bugs in Linux and FreeBSD kernels (probably |
451 | around some known bugs in Linux and FreeBSD kernels (probably |
| 407 | others, too), but that might fail, so you really really should check |
452 | others, too), but that might fail, so you really really should check |
| 408 | the return value of "aio_sendfile" - fewre bytes than expected might |
453 | the return value of "aio_sendfile" - fewer bytes than expected might |
| 409 | have been transferred. |
454 | have been transferred. |
| 410 | |
455 | |
| 411 | aio_readahead $fh,$offset,$length, $callback->($retval) |
456 | aio_readahead $fh,$offset,$length, $callback->($retval) |
| 412 | "aio_readahead" populates the page cache with data from a file so |
457 | "aio_readahead" populates the page cache with data from a file so |
| 413 | that subsequent reads from that file will not block on disk I/O. The |
458 | that subsequent reads from that file will not block on disk I/O. The |
| … | |
… | |
| 417 | to a page boundary and bytes are read up to the next page boundary |
462 | to a page boundary and bytes are read up to the next page boundary |
| 418 | greater than or equal to (off-set+length). "aio_readahead" does not |
463 | greater than or equal to (off-set+length). "aio_readahead" does not |
| 419 | read beyond the end of the file. The current file offset of the file |
464 | read beyond the end of the file. The current file offset of the file |
| 420 | is left unchanged. |
465 | is left unchanged. |
| 421 | |
466 | |
| 422 | If that syscall doesn't exist (likely if your OS isn't Linux) it |
467 | If that syscall doesn't exist (likely if your kernel isn't Linux) it |
| 423 | will be emulated by simply reading the data, which would have a |
468 | will be emulated by simply reading the data, which would have a |
| 424 | similar effect. |
469 | similar effect. |
| 425 | |
470 | |
| 426 | aio_stat $fh_or_path, $callback->($status) |
471 | aio_stat $fh_or_path, $callback->($status) |
| 427 | aio_lstat $fh, $callback->($status) |
472 | aio_lstat $fh, $callback->($status) |
| … | |
… | |
| 525 | aio_chown "path", 0, undef; |
570 | aio_chown "path", 0, undef; |
| 526 | |
571 | |
| 527 | aio_truncate $fh_or_path, $offset, $callback->($status) |
572 | aio_truncate $fh_or_path, $offset, $callback->($status) |
| 528 | Works like truncate(2) or ftruncate(2). |
573 | Works like truncate(2) or ftruncate(2). |
| 529 | |
574 | |
|
|
575 | aio_allocate $fh, $mode, $offset, $len, $callback->($status) |
|
|
576 | Allocates or frees disk space according to the $mode argument. See |
|
|
577 | the linux "fallocate" documentation for details. |
|
|
578 | |
|
|
579 | $mode is usually 0 or "IO::AIO::FALLOC_FL_KEEP_SIZE" to allocate |
|
|
580 | space, or "IO::AIO::FALLOC_FL_PUNCH_HOLE | |
|
|
581 | IO::AIO::FALLOC_FL_KEEP_SIZE", to deallocate a file range. |
|
|
582 | |
|
|
583 | IO::AIO also supports "FALLOC_FL_COLLAPSE_RANGE", to remove a range |
|
|
584 | (without leaving a hole), "FALLOC_FL_ZERO_RANGE", to zero a range, |
|
|
585 | "FALLOC_FL_INSERT_RANGE" to insert a range and |
|
|
586 | "FALLOC_FL_UNSHARE_RANGE" to unshare shared blocks (see your |
|
|
587 | fallocate(2) manpage). |
|
|
588 | |
|
|
589 | The file system block size used by "fallocate" is presumably the |
|
|
590 | "f_bsize" returned by "statvfs", but different filesystems and |
|
|
591 | filetypes can dictate other limitations. |
|
|
592 | |
|
|
593 | If "fallocate" isn't available or cannot be emulated (currently no |
|
|
594 | emulation will be attempted), passes -1 and sets $! to "ENOSYS". |
|
|
595 | |
| 530 | aio_chmod $fh_or_path, $mode, $callback->($status) |
596 | aio_chmod $fh_or_path, $mode, $callback->($status) |
| 531 | Works like perl's "chmod" function. |
597 | Works like perl's "chmod" function. |
| 532 | |
598 | |
| 533 | aio_unlink $pathname, $callback->($status) |
599 | aio_unlink $pathname, $callback->($status) |
| 534 | Asynchronously unlink (delete) a file and call the callback with the |
600 | Asynchronously unlink (delete) a file and call the callback with the |
| 535 | result code. |
601 | result code. |
| 536 | |
602 | |
| 537 | aio_mknod $path, $mode, $dev, $callback->($status) |
603 | aio_mknod $pathname, $mode, $dev, $callback->($status) |
| 538 | [EXPERIMENTAL] |
604 | [EXPERIMENTAL] |
| 539 | |
605 | |
| 540 | Asynchronously create a device node (or fifo). See mknod(2). |
606 | Asynchronously create a device node (or fifo). See mknod(2). |
| 541 | |
607 | |
| 542 | The only (POSIX-) portable way of calling this function is: |
608 | The only (POSIX-) portable way of calling this function is: |
| 543 | |
609 | |
| 544 | aio_mknod $path, IO::AIO::S_IFIFO | $mode, 0, sub { ... |
610 | aio_mknod $pathname, IO::AIO::S_IFIFO | $mode, 0, sub { ... |
| 545 | |
611 | |
| 546 | See "aio_stat" for info about some potentially helpful extra |
612 | See "aio_stat" for info about some potentially helpful extra |
| 547 | constants and functions. |
613 | constants and functions. |
| 548 | |
614 | |
| 549 | aio_link $srcpath, $dstpath, $callback->($status) |
615 | aio_link $srcpath, $dstpath, $callback->($status) |
| … | |
… | |
| 553 | aio_symlink $srcpath, $dstpath, $callback->($status) |
619 | aio_symlink $srcpath, $dstpath, $callback->($status) |
| 554 | Asynchronously create a new symbolic link to the existing object at |
620 | Asynchronously create a new symbolic link to the existing object at |
| 555 | $srcpath at the path $dstpath and call the callback with the result |
621 | $srcpath at the path $dstpath and call the callback with the result |
| 556 | code. |
622 | code. |
| 557 | |
623 | |
| 558 | aio_readlink $path, $callback->($link) |
624 | aio_readlink $pathname, $callback->($link) |
| 559 | Asynchronously read the symlink specified by $path and pass it to |
625 | Asynchronously read the symlink specified by $path and pass it to |
| 560 | the callback. If an error occurs, nothing or undef gets passed to |
626 | the callback. If an error occurs, nothing or undef gets passed to |
| 561 | the callback. |
627 | the callback. |
| 562 | |
628 | |
| 563 | aio_realpath $path, $callback->($path) |
629 | aio_realpath $pathname, $callback->($path) |
| 564 | Asynchronously make the path absolute and resolve any symlinks in |
630 | Asynchronously make the path absolute and resolve any symlinks in |
| 565 | $path. The resulting path only consists of directories (Same as |
631 | $path. The resulting path only consists of directories (same as |
| 566 | Cwd::realpath). |
632 | Cwd::realpath). |
| 567 | |
633 | |
| 568 | This request can be used to get the absolute path of the current |
634 | This request can be used to get the absolute path of the current |
| 569 | working directory by passing it a path of . (a single dot). |
635 | working directory by passing it a path of . (a single dot). |
| 570 | |
636 | |
| 571 | aio_rename $srcpath, $dstpath, $callback->($status) |
637 | aio_rename $srcpath, $dstpath, $callback->($status) |
| 572 | Asynchronously rename the object at $srcpath to $dstpath, just as |
638 | Asynchronously rename the object at $srcpath to $dstpath, just as |
| 573 | rename(2) and call the callback with the result code. |
639 | rename(2) and call the callback with the result code. |
|
|
640 | |
|
|
641 | On systems that support the AIO::WD working directory abstraction |
|
|
642 | natively, the case "[$wd, "."]" as $srcpath is specialcased - |
|
|
643 | instead of failing, "rename" is called on the absolute path of $wd. |
|
|
644 | |
|
|
645 | aio_rename2 $srcpath, $dstpath, $flags, $callback->($status) |
|
|
646 | Basically a version of "aio_rename" with an additional $flags |
|
|
647 | argument. Calling this with "$flags=0" is the same as calling |
|
|
648 | "aio_rename". |
|
|
649 | |
|
|
650 | Non-zero flags are currently only supported on GNU/Linux systems |
|
|
651 | that support renameat2. Other systems fail with "ENOSYS" in this |
|
|
652 | case. |
|
|
653 | |
|
|
654 | The following constants are available (missing ones are, as usual |
|
|
655 | 0), see renameat2(2) for details: |
|
|
656 | |
|
|
657 | "IO::AIO::RENAME_NOREPLACE", "IO::AIO::RENAME_EXCHANGE" and |
|
|
658 | "IO::AIO::RENAME_WHITEOUT". |
| 574 | |
659 | |
| 575 | aio_mkdir $pathname, $mode, $callback->($status) |
660 | aio_mkdir $pathname, $mode, $callback->($status) |
| 576 | Asynchronously mkdir (create) a directory and call the callback with |
661 | Asynchronously mkdir (create) a directory and call the callback with |
| 577 | the result code. $mode will be modified by the umask at the time the |
662 | the result code. $mode will be modified by the umask at the time the |
| 578 | request is executed, so do not change your umask. |
663 | request is executed, so do not change your umask. |
| 579 | |
664 | |
| 580 | aio_rmdir $pathname, $callback->($status) |
665 | aio_rmdir $pathname, $callback->($status) |
| 581 | Asynchronously rmdir (delete) a directory and call the callback with |
666 | Asynchronously rmdir (delete) a directory and call the callback with |
| 582 | the result code. |
667 | the result code. |
| 583 | |
668 | |
|
|
669 | On systems that support the AIO::WD working directory abstraction |
|
|
670 | natively, the case "[$wd, "."]" is specialcased - instead of |
|
|
671 | failing, "rmdir" is called on the absolute path of $wd. |
|
|
672 | |
| 584 | aio_readdir $pathname, $callback->($entries) |
673 | aio_readdir $pathname, $callback->($entries) |
| 585 | Unlike the POSIX call of the same name, "aio_readdir" reads an |
674 | Unlike the POSIX call of the same name, "aio_readdir" reads an |
| 586 | entire directory (i.e. opendir + readdir + closedir). The entries |
675 | entire directory (i.e. opendir + readdir + closedir). The entries |
| 587 | will not be sorted, and will NOT include the "." and ".." entries. |
676 | will not be sorted, and will NOT include the "." and ".." entries. |
| 588 | |
677 | |
| 589 | The callback is passed a single argument which is either "undef" or |
678 | The callback is passed a single argument which is either "undef" or |
| 590 | an array-ref with the filenames. |
679 | an array-ref with the filenames. |
| 591 | |
680 | |
| 592 | aio_readdirx $pathname, $flags, $callback->($entries, $flags) |
681 | aio_readdirx $pathname, $flags, $callback->($entries, $flags) |
| 593 | Quite similar to "aio_readdir", but the $flags argument allows to |
682 | Quite similar to "aio_readdir", but the $flags argument allows one |
| 594 | tune behaviour and output format. In case of an error, $entries will |
683 | to tune behaviour and output format. In case of an error, $entries |
| 595 | be "undef". |
684 | will be "undef". |
| 596 | |
685 | |
| 597 | The flags are a combination of the following constants, ORed |
686 | The flags are a combination of the following constants, ORed |
| 598 | together (the flags will also be passed to the callback, possibly |
687 | together (the flags will also be passed to the callback, possibly |
| 599 | modified): |
688 | modified): |
| 600 | |
689 | |
| … | |
… | |
| 645 | optimal stat order. |
734 | optimal stat order. |
| 646 | |
735 | |
| 647 | IO::AIO::READDIR_FOUND_UNKNOWN |
736 | IO::AIO::READDIR_FOUND_UNKNOWN |
| 648 | This flag should not be set when calling "aio_readdirx". |
737 | This flag should not be set when calling "aio_readdirx". |
| 649 | Instead, it is being set by "aio_readdirx", when any of the |
738 | Instead, it is being set by "aio_readdirx", when any of the |
| 650 | $type's found were "IO::AIO::DT_UNKNOWN". The absense of this |
739 | $type's found were "IO::AIO::DT_UNKNOWN". The absence of this |
| 651 | flag therefore indicates that all $type's are known, which can |
740 | flag therefore indicates that all $type's are known, which can |
| 652 | be used to speed up some algorithms. |
741 | be used to speed up some algorithms. |
| 653 | |
742 | |
|
|
743 | aio_slurp $pathname, $offset, $length, $data, $callback->($status) |
|
|
744 | Opens, reads and closes the given file. The data is put into $data, |
|
|
745 | which is resized as required. |
|
|
746 | |
|
|
747 | If $offset is negative, then it is counted from the end of the file. |
|
|
748 | |
|
|
749 | If $length is zero, then the remaining length of the file is used. |
|
|
750 | Also, in this case, the same limitations to modifying $data apply as |
|
|
751 | when IO::AIO::mmap is used, i.e. it must only be modified in-place |
|
|
752 | with "substr". If the size of the file is known, specifying a |
|
|
753 | non-zero $length results in a performance advantage. |
|
|
754 | |
|
|
755 | This request is similar to the older "aio_load" request, but since |
|
|
756 | it is a single request, it might be more efficient to use. |
|
|
757 | |
|
|
758 | Example: load /etc/passwd into $passwd. |
|
|
759 | |
|
|
760 | my $passwd; |
|
|
761 | aio_slurp "/etc/passwd", 0, 0, $passwd, sub { |
|
|
762 | $_[0] >= 0 |
|
|
763 | or die "/etc/passwd: $!\n"; |
|
|
764 | |
|
|
765 | printf "/etc/passwd is %d bytes long, and contains:\n", length $passwd; |
|
|
766 | print $passwd; |
|
|
767 | }; |
|
|
768 | IO::AIO::flush; |
|
|
769 | |
| 654 | aio_load $path, $data, $callback->($status) |
770 | aio_load $pathname, $data, $callback->($status) |
| 655 | This is a composite request that tries to fully load the given file |
771 | This is a composite request that tries to fully load the given file |
| 656 | into memory. Status is the same as with aio_read. |
772 | into memory. Status is the same as with aio_read. |
|
|
773 | |
|
|
774 | Using "aio_slurp" might be more efficient, as it is a single |
|
|
775 | request. |
| 657 | |
776 | |
| 658 | aio_copy $srcpath, $dstpath, $callback->($status) |
777 | aio_copy $srcpath, $dstpath, $callback->($status) |
| 659 | Try to copy the *file* (directories not supported as either source |
778 | Try to copy the *file* (directories not supported as either source |
| 660 | or destination) from $srcpath to $dstpath and call the callback with |
779 | or destination) from $srcpath to $dstpath and call the callback with |
| 661 | a status of 0 (ok) or -1 (error, see $!). |
780 | a status of 0 (ok) or -1 (error, see $!). |
| 662 | |
781 | |
|
|
782 | Existing destination files will be truncated. |
|
|
783 | |
| 663 | This is a composite request that creates the destination file with |
784 | This is a composite request that creates the destination file with |
| 664 | mode 0200 and copies the contents of the source file into it using |
785 | mode 0200 and copies the contents of the source file into it using |
| 665 | "aio_sendfile", followed by restoring atime, mtime, access mode and |
786 | "aio_sendfile", followed by restoring atime, mtime, access mode and |
| 666 | uid/gid, in that order. |
787 | uid/gid, in that order. |
| 667 | |
788 | |
| … | |
… | |
| 676 | |
797 | |
| 677 | This is a composite request that tries to rename(2) the file first; |
798 | This is a composite request that tries to rename(2) the file first; |
| 678 | if rename fails with "EXDEV", it copies the file with "aio_copy" |
799 | if rename fails with "EXDEV", it copies the file with "aio_copy" |
| 679 | and, if that is successful, unlinks the $srcpath. |
800 | and, if that is successful, unlinks the $srcpath. |
| 680 | |
801 | |
| 681 | aio_scandir $path, $maxreq, $callback->($dirs, $nondirs) |
802 | aio_scandir $pathname, $maxreq, $callback->($dirs, $nondirs) |
| 682 | Scans a directory (similar to "aio_readdir") but additionally tries |
803 | Scans a directory (similar to "aio_readdir") but additionally tries |
| 683 | to efficiently separate the entries of directory $path into two sets |
804 | to efficiently separate the entries of directory $path into two sets |
| 684 | of names, directories you can recurse into (directories), and ones |
805 | of names, directories you can recurse into (directories), and ones |
| 685 | you cannot recurse into (everything else, including symlinks to |
806 | you cannot recurse into (everything else, including symlinks to |
| 686 | directories). |
807 | directories). |
| 687 | |
808 | |
| 688 | "aio_scandir" is a composite request that creates of many sub |
809 | "aio_scandir" is a composite request that generates many sub |
| 689 | requests_ $maxreq specifies the maximum number of outstanding aio |
810 | requests. $maxreq specifies the maximum number of outstanding aio |
| 690 | requests that this function generates. If it is "<= 0", then a |
811 | requests that this function generates. If it is "<= 0", then a |
| 691 | suitable default will be chosen (currently 4). |
812 | suitable default will be chosen (currently 4). |
| 692 | |
813 | |
| 693 | On error, the callback is called without arguments, otherwise it |
814 | On error, the callback is called without arguments, otherwise it |
| 694 | receives two array-refs with path-relative entry names. |
815 | receives two array-refs with path-relative entry names. |
| … | |
… | |
| 719 | Then entries will be sorted into likely directories a non-initial |
840 | Then entries will be sorted into likely directories a non-initial |
| 720 | dot currently) and likely non-directories (see "aio_readdirx"). Then |
841 | dot currently) and likely non-directories (see "aio_readdirx"). Then |
| 721 | every entry plus an appended "/." will be "stat"'ed, likely |
842 | every entry plus an appended "/." will be "stat"'ed, likely |
| 722 | directories first, in order of their inode numbers. If that |
843 | directories first, in order of their inode numbers. If that |
| 723 | succeeds, it assumes that the entry is a directory or a symlink to |
844 | succeeds, it assumes that the entry is a directory or a symlink to |
| 724 | directory (which will be checked seperately). This is often faster |
845 | directory (which will be checked separately). This is often faster |
| 725 | than stat'ing the entry itself because filesystems might detect the |
846 | than stat'ing the entry itself because filesystems might detect the |
| 726 | type of the entry without reading the inode data (e.g. ext2fs |
847 | type of the entry without reading the inode data (e.g. ext2fs |
| 727 | filetype feature), even on systems that cannot return the filetype |
848 | filetype feature), even on systems that cannot return the filetype |
| 728 | information on readdir. |
849 | information on readdir. |
| 729 | |
850 | |
| … | |
… | |
| 735 | |
856 | |
| 736 | It will also likely work on non-POSIX filesystems with reduced |
857 | It will also likely work on non-POSIX filesystems with reduced |
| 737 | efficiency as those tend to return 0 or 1 as link counts, which |
858 | efficiency as those tend to return 0 or 1 as link counts, which |
| 738 | disables the directory counting heuristic. |
859 | disables the directory counting heuristic. |
| 739 | |
860 | |
| 740 | aio_rmtree $path, $callback->($status) |
861 | aio_rmtree $pathname, $callback->($status) |
| 741 | Delete a directory tree starting (and including) $path, return the |
862 | Delete a directory tree starting (and including) $path, return the |
| 742 | status of the final "rmdir" only. This is a composite request that |
863 | status of the final "rmdir" only. This is a composite request that |
| 743 | uses "aio_scandir" to recurse into and rmdir directories, and unlink |
864 | uses "aio_scandir" to recurse into and rmdir directories, and unlink |
| 744 | everything else. |
865 | everything else. |
| 745 | |
866 | |
|
|
867 | aio_fcntl $fh, $cmd, $arg, $callback->($status) |
|
|
868 | aio_ioctl $fh, $request, $buf, $callback->($status) |
|
|
869 | These work just like the "fcntl" and "ioctl" built-in functions, |
|
|
870 | except they execute asynchronously and pass the return value to the |
|
|
871 | callback. |
|
|
872 | |
|
|
873 | Both calls can be used for a lot of things, some of which make more |
|
|
874 | sense to run asynchronously in their own thread, while some others |
|
|
875 | make less sense. For example, calls that block waiting for external |
|
|
876 | events, such as locking, will also lock down an I/O thread while it |
|
|
877 | is waiting, which can deadlock the whole I/O system. At the same |
|
|
878 | time, there might be no alternative to using a thread to wait. |
|
|
879 | |
|
|
880 | So in general, you should only use these calls for things that do |
|
|
881 | (filesystem) I/O, not for things that wait for other events |
|
|
882 | (network, other processes), although if you are careful and know |
|
|
883 | what you are doing, you still can. |
|
|
884 | |
|
|
885 | The following constants are available (missing ones are, as usual |
|
|
886 | 0): |
|
|
887 | |
|
|
888 | "F_DUPFD_CLOEXEC", |
|
|
889 | |
|
|
890 | "F_OFD_GETLK", "F_OFD_SETLK", "F_OFD_GETLKW", |
|
|
891 | |
|
|
892 | "FIFREEZE", "FITHAW", "FITRIM", "FICLONE", "FICLONERANGE", |
|
|
893 | "FIDEDUPERANGE". |
|
|
894 | |
|
|
895 | "FS_IOC_GETFLAGS", "FS_IOC_SETFLAGS", "FS_IOC_GETVERSION", |
|
|
896 | "FS_IOC_SETVERSION", "FS_IOC_FIEMAP". |
|
|
897 | |
|
|
898 | "FS_IOC_FSGETXATTR", "FS_IOC_FSSETXATTR", |
|
|
899 | "FS_IOC_SET_ENCRYPTION_POLICY", "FS_IOC_GET_ENCRYPTION_PWSALT", |
|
|
900 | "FS_IOC_GET_ENCRYPTION_POLICY", "FS_KEY_DESCRIPTOR_SIZE". |
|
|
901 | |
|
|
902 | "FS_SECRM_FL", "FS_UNRM_FL", "FS_COMPR_FL", "FS_SYNC_FL", |
|
|
903 | "FS_IMMUTABLE_FL", "FS_APPEND_FL", "FS_NODUMP_FL", "FS_NOATIME_FL", |
|
|
904 | "FS_DIRTY_FL", "FS_COMPRBLK_FL", "FS_NOCOMP_FL", "FS_ENCRYPT_FL", |
|
|
905 | "FS_BTREE_FL", "FS_INDEX_FL", "FS_JOURNAL_DATA_FL", "FS_NOTAIL_FL", |
|
|
906 | "FS_DIRSYNC_FL", "FS_TOPDIR_FL", "FS_FL_USER_MODIFIABLE". |
|
|
907 | |
|
|
908 | "FS_XFLAG_REALTIME", "FS_XFLAG_PREALLOC", "FS_XFLAG_IMMUTABLE", |
|
|
909 | "FS_XFLAG_APPEND", "FS_XFLAG_SYNC", "FS_XFLAG_NOATIME", |
|
|
910 | "FS_XFLAG_NODUMP", "FS_XFLAG_RTINHERIT", "FS_XFLAG_PROJINHERIT", |
|
|
911 | "FS_XFLAG_NOSYMLINKS", "FS_XFLAG_EXTSIZE", "FS_XFLAG_EXTSZINHERIT", |
|
|
912 | "FS_XFLAG_NODEFRAG", "FS_XFLAG_FILESTREAM", "FS_XFLAG_DAX", |
|
|
913 | "FS_XFLAG_HASATTR", |
|
|
914 | |
| 746 | aio_sync $callback->($status) |
915 | aio_sync $callback->($status) |
| 747 | Asynchronously call sync and call the callback when finished. |
916 | Asynchronously call sync and call the callback when finished. |
| 748 | |
917 | |
| 749 | aio_fsync $fh, $callback->($status) |
918 | aio_fsync $fh, $callback->($status) |
| 750 | Asynchronously call fsync on the given filehandle and call the |
919 | Asynchronously call fsync on the given filehandle and call the |
| … | |
… | |
| 754 | Asynchronously call fdatasync on the given filehandle and call the |
923 | Asynchronously call fdatasync on the given filehandle and call the |
| 755 | callback with the fdatasync result code. |
924 | callback with the fdatasync result code. |
| 756 | |
925 | |
| 757 | If this call isn't available because your OS lacks it or it couldn't |
926 | If this call isn't available because your OS lacks it or it couldn't |
| 758 | be detected, it will be emulated by calling "fsync" instead. |
927 | be detected, it will be emulated by calling "fsync" instead. |
|
|
928 | |
|
|
929 | aio_syncfs $fh, $callback->($status) |
|
|
930 | Asynchronously call the syncfs syscall to sync the filesystem |
|
|
931 | associated to the given filehandle and call the callback with the |
|
|
932 | syncfs result code. If syncfs is not available, calls sync(), but |
|
|
933 | returns -1 and sets errno to "ENOSYS" nevertheless. |
| 759 | |
934 | |
| 760 | aio_sync_file_range $fh, $offset, $nbytes, $flags, $callback->($status) |
935 | aio_sync_file_range $fh, $offset, $nbytes, $flags, $callback->($status) |
| 761 | Sync the data portion of the file specified by $offset and $length |
936 | Sync the data portion of the file specified by $offset and $length |
| 762 | to disk (but NOT the metadata), by calling the Linux-specific |
937 | to disk (but NOT the metadata), by calling the Linux-specific |
| 763 | sync_file_range call. If sync_file_range is not available or it |
938 | sync_file_range call. If sync_file_range is not available or it |
| … | |
… | |
| 767 | "IO::AIO::SYNC_FILE_RANGE_WAIT_BEFORE", |
942 | "IO::AIO::SYNC_FILE_RANGE_WAIT_BEFORE", |
| 768 | "IO::AIO::SYNC_FILE_RANGE_WRITE" and |
943 | "IO::AIO::SYNC_FILE_RANGE_WRITE" and |
| 769 | "IO::AIO::SYNC_FILE_RANGE_WAIT_AFTER": refer to the sync_file_range |
944 | "IO::AIO::SYNC_FILE_RANGE_WAIT_AFTER": refer to the sync_file_range |
| 770 | manpage for details. |
945 | manpage for details. |
| 771 | |
946 | |
| 772 | aio_pathsync $path, $callback->($status) |
947 | aio_pathsync $pathname, $callback->($status) |
| 773 | This request tries to open, fsync and close the given path. This is |
948 | This request tries to open, fsync and close the given path. This is |
| 774 | a composite request intended to sync directories after directory |
949 | a composite request intended to sync directories after directory |
| 775 | operations (E.g. rename). This might not work on all operating |
950 | operations (E.g. rename). This might not work on all operating |
| 776 | systems or have any specific effect, but usually it makes sure that |
951 | systems or have any specific effect, but usually it makes sure that |
| 777 | directory changes get written to disc. It works for anything that |
952 | directory changes get written to disc. It works for anything that |
| … | |
… | |
| 780 | Future versions of this function might fall back to other methods |
955 | Future versions of this function might fall back to other methods |
| 781 | when "fsync" on the directory fails (such as calling "sync"). |
956 | when "fsync" on the directory fails (such as calling "sync"). |
| 782 | |
957 | |
| 783 | Passes 0 when everything went ok, and -1 on error. |
958 | Passes 0 when everything went ok, and -1 on error. |
| 784 | |
959 | |
| 785 | aio_msync $scalar, $offset = 0, $length = undef, flags = 0, |
960 | aio_msync $scalar, $offset = 0, $length = undef, flags = MS_SYNC, |
| 786 | $callback->($status) |
961 | $callback->($status) |
| 787 | This is a rather advanced IO::AIO call, which only works on |
962 | This is a rather advanced IO::AIO call, which only works on |
| 788 | mmap(2)ed scalars (see the "IO::AIO::mmap" function, although it |
963 | mmap(2)ed scalars (see the "IO::AIO::mmap" function, although it |
| 789 | also works on data scalars managed by the Sys::Mmap or Mmap modules, |
964 | also works on data scalars managed by the Sys::Mmap or Mmap modules, |
| 790 | note that the scalar must only be modified in-place while an aio |
965 | note that the scalar must only be modified in-place while an aio |
| … | |
… | |
| 792 | |
967 | |
| 793 | It calls the "msync" function of your OS, if available, with the |
968 | It calls the "msync" function of your OS, if available, with the |
| 794 | memory area starting at $offset in the string and ending $length |
969 | memory area starting at $offset in the string and ending $length |
| 795 | bytes later. If $length is negative, counts from the end, and if |
970 | bytes later. If $length is negative, counts from the end, and if |
| 796 | $length is "undef", then it goes till the end of the string. The |
971 | $length is "undef", then it goes till the end of the string. The |
| 797 | flags can be a combination of "IO::AIO::MS_ASYNC", |
972 | flags can be either "IO::AIO::MS_ASYNC" or "IO::AIO::MS_SYNC", plus |
| 798 | "IO::AIO::MS_INVALIDATE" and "IO::AIO::MS_SYNC". |
973 | an optional "IO::AIO::MS_INVALIDATE". |
| 799 | |
974 | |
| 800 | aio_mtouch $scalar, $offset = 0, $length = undef, flags = 0, |
975 | aio_mtouch $scalar, $offset = 0, $length = undef, flags = 0, |
| 801 | $callback->($status) |
976 | $callback->($status) |
| 802 | This is a rather advanced IO::AIO call, which works best on |
977 | This is a rather advanced IO::AIO call, which works best on |
| 803 | mmap(2)ed scalars. |
978 | mmap(2)ed scalars. |
| 804 | |
979 | |
| 805 | It touches (reads or writes) all memory pages in the specified range |
980 | It touches (reads or writes) all memory pages in the specified range |
| 806 | inside the scalar. All caveats and parameters are the same as for |
981 | inside the scalar. All caveats and parameters are the same as for |
| 807 | "aio_msync", above, except for flags, which must be either 0 (which |
982 | "aio_msync", above, except for flags, which must be either 0 (which |
| 808 | reads all pages and ensures they are instantiated) or |
983 | reads all pages and ensures they are instantiated) or |
| 809 | "IO::AIO::MT_MODIFY", which modifies the memory page s(by reading |
984 | "IO::AIO::MT_MODIFY", which modifies the memory pages (by reading |
| 810 | and writing an octet from it, which dirties the page). |
985 | and writing an octet from it, which dirties the page). |
| 811 | |
986 | |
| 812 | aio_mlock $scalar, $offset = 0, $length = undef, $callback->($status) |
987 | aio_mlock $scalar, $offset = 0, $length = undef, $callback->($status) |
| 813 | This is a rather advanced IO::AIO call, which works best on |
988 | This is a rather advanced IO::AIO call, which works best on |
| 814 | mmap(2)ed scalars. |
989 | mmap(2)ed scalars. |
| … | |
… | |
| 846 | |
1021 | |
| 847 | Example: asynchronously lock all current and future pages into |
1022 | Example: asynchronously lock all current and future pages into |
| 848 | memory. |
1023 | memory. |
| 849 | |
1024 | |
| 850 | aio_mlockall IO::AIO::MCL_FUTURE; |
1025 | aio_mlockall IO::AIO::MCL_FUTURE; |
|
|
1026 | |
|
|
1027 | aio_fiemap $fh, $start, $length, $flags, $count, $cb->(\@extents) |
|
|
1028 | Queries the extents of the given file (by calling the Linux "FIEMAP" |
|
|
1029 | ioctl, see <http://cvs.schmorp.de/IO-AIO/doc/fiemap.txt> for |
|
|
1030 | details). If the ioctl is not available on your OS, then this |
|
|
1031 | request will fail with "ENOSYS". |
|
|
1032 | |
|
|
1033 | $start is the starting offset to query extents for, $length is the |
|
|
1034 | size of the range to query - if it is "undef", then the whole file |
|
|
1035 | will be queried. |
|
|
1036 | |
|
|
1037 | $flags is a combination of flags ("IO::AIO::FIEMAP_FLAG_SYNC" or |
|
|
1038 | "IO::AIO::FIEMAP_FLAG_XATTR" - "IO::AIO::FIEMAP_FLAGS_COMPAT" is |
|
|
1039 | also exported), and is normally 0 or "IO::AIO::FIEMAP_FLAG_SYNC" to |
|
|
1040 | query the data portion. |
|
|
1041 | |
|
|
1042 | $count is the maximum number of extent records to return. If it is |
|
|
1043 | "undef", then IO::AIO queries all extents of the range. As a very |
|
|
1044 | special case, if it is 0, then the callback receives the number of |
|
|
1045 | extents instead of the extents themselves (which is unreliable, see |
|
|
1046 | below). |
|
|
1047 | |
|
|
1048 | If an error occurs, the callback receives no arguments. The special |
|
|
1049 | "errno" value "IO::AIO::EBADR" is available to test for flag errors. |
|
|
1050 | |
|
|
1051 | Otherwise, the callback receives an array reference with extent |
|
|
1052 | structures. Each extent structure is an array reference itself, with |
|
|
1053 | the following members: |
|
|
1054 | |
|
|
1055 | [$logical, $physical, $length, $flags] |
|
|
1056 | |
|
|
1057 | Flags is any combination of the following flag values (typically |
|
|
1058 | either 0 or "IO::AIO::FIEMAP_EXTENT_LAST" (1)): |
|
|
1059 | |
|
|
1060 | "IO::AIO::FIEMAP_EXTENT_LAST", "IO::AIO::FIEMAP_EXTENT_UNKNOWN", |
|
|
1061 | "IO::AIO::FIEMAP_EXTENT_DELALLOC", "IO::AIO::FIEMAP_EXTENT_ENCODED", |
|
|
1062 | "IO::AIO::FIEMAP_EXTENT_DATA_ENCRYPTED", |
|
|
1063 | "IO::AIO::FIEMAP_EXTENT_NOT_ALIGNED", |
|
|
1064 | "IO::AIO::FIEMAP_EXTENT_DATA_INLINE", |
|
|
1065 | "IO::AIO::FIEMAP_EXTENT_DATA_TAIL", |
|
|
1066 | "IO::AIO::FIEMAP_EXTENT_UNWRITTEN", "IO::AIO::FIEMAP_EXTENT_MERGED" |
|
|
1067 | or "IO::AIO::FIEMAP_EXTENT_SHARED". |
|
|
1068 | |
|
|
1069 | At the time of this writing (Linux 3.2), this request is unreliable |
|
|
1070 | unless $count is "undef", as the kernel has all sorts of bugs |
|
|
1071 | preventing it to return all extents of a range for files with a |
|
|
1072 | large number of extents. The code (only) works around all these |
|
|
1073 | issues if $count is "undef". |
| 851 | |
1074 | |
| 852 | aio_group $callback->(...) |
1075 | aio_group $callback->(...) |
| 853 | This is a very special aio request: Instead of doing something, it |
1076 | This is a very special aio request: Instead of doing something, it |
| 854 | is a container for other aio requests, which is useful if you want |
1077 | is a container for other aio requests, which is useful if you want |
| 855 | to bundle many requests into a single, composite, request with a |
1078 | to bundle many requests into a single, composite, request with a |
| … | |
… | |
| 889 | While it is theoretically handy to have simple I/O scheduling |
1112 | While it is theoretically handy to have simple I/O scheduling |
| 890 | requests like sleep and file handle readable/writable, the overhead |
1113 | requests like sleep and file handle readable/writable, the overhead |
| 891 | this creates is immense (it blocks a thread for a long time) so do |
1114 | this creates is immense (it blocks a thread for a long time) so do |
| 892 | not use this function except to put your application under |
1115 | not use this function except to put your application under |
| 893 | artificial I/O pressure. |
1116 | artificial I/O pressure. |
|
|
1117 | |
|
|
1118 | IO::AIO::WD - multiple working directories |
|
|
1119 | Your process only has one current working directory, which is used by |
|
|
1120 | all threads. This makes it hard to use relative paths (some other |
|
|
1121 | component could call "chdir" at any time, and it is hard to control when |
|
|
1122 | the path will be used by IO::AIO). |
|
|
1123 | |
|
|
1124 | One solution for this is to always use absolute paths. This usually |
|
|
1125 | works, but can be quite slow (the kernel has to walk the whole path on |
|
|
1126 | every access), and can also be a hassle to implement. |
|
|
1127 | |
|
|
1128 | Newer POSIX systems have a number of functions (openat, fdopendir, |
|
|
1129 | futimensat and so on) that make it possible to specify working |
|
|
1130 | directories per operation. |
|
|
1131 | |
|
|
1132 | For portability, and because the clowns who "designed", or shall I |
|
|
1133 | write, perpetrated this new interface were obviously half-drunk, this |
|
|
1134 | abstraction cannot be perfect, though. |
|
|
1135 | |
|
|
1136 | IO::AIO allows you to convert directory paths into a so-called |
|
|
1137 | IO::AIO::WD object. This object stores the canonicalised, absolute |
|
|
1138 | version of the path, and on systems that allow it, also a directory file |
|
|
1139 | descriptor. |
|
|
1140 | |
|
|
1141 | Everywhere where a pathname is accepted by IO::AIO (e.g. in "aio_stat" |
|
|
1142 | or "aio_unlink"), one can specify an array reference with an IO::AIO::WD |
|
|
1143 | object and a pathname instead (or the IO::AIO::WD object alone, which |
|
|
1144 | gets interpreted as "[$wd, "."]"). If the pathname is absolute, the |
|
|
1145 | IO::AIO::WD object is ignored, otherwise the pathname is resolved |
|
|
1146 | relative to that IO::AIO::WD object. |
|
|
1147 | |
|
|
1148 | For example, to get a wd object for /etc and then stat passwd inside, |
|
|
1149 | you would write: |
|
|
1150 | |
|
|
1151 | aio_wd "/etc", sub { |
|
|
1152 | my $etcdir = shift; |
|
|
1153 | |
|
|
1154 | # although $etcdir can be undef on error, there is generally no reason |
|
|
1155 | # to check for errors here, as aio_stat will fail with ENOENT |
|
|
1156 | # when $etcdir is undef. |
|
|
1157 | |
|
|
1158 | aio_stat [$etcdir, "passwd"], sub { |
|
|
1159 | # yay |
|
|
1160 | }; |
|
|
1161 | }; |
|
|
1162 | |
|
|
1163 | The fact that "aio_wd" is a request and not a normal function shows that |
|
|
1164 | creating an IO::AIO::WD object is itself a potentially blocking |
|
|
1165 | operation, which is why it is done asynchronously. |
|
|
1166 | |
|
|
1167 | To stat the directory obtained with "aio_wd" above, one could write |
|
|
1168 | either of the following three request calls: |
|
|
1169 | |
|
|
1170 | aio_lstat "/etc" , sub { ... # pathname as normal string |
|
|
1171 | aio_lstat [$wd, "."], sub { ... # "." relative to $wd (i.e. $wd itself) |
|
|
1172 | aio_lstat $wd , sub { ... # shorthand for the previous |
|
|
1173 | |
|
|
1174 | As with normal pathnames, IO::AIO keeps a copy of the working directory |
|
|
1175 | object and the pathname string, so you could write the following without |
|
|
1176 | causing any issues due to $path getting reused: |
|
|
1177 | |
|
|
1178 | my $path = [$wd, undef]; |
|
|
1179 | |
|
|
1180 | for my $name (qw(abc def ghi)) { |
|
|
1181 | $path->[1] = $name; |
|
|
1182 | aio_stat $path, sub { |
|
|
1183 | # ... |
|
|
1184 | }; |
|
|
1185 | } |
|
|
1186 | |
|
|
1187 | There are some caveats: when directories get renamed (or deleted), the |
|
|
1188 | pathname string doesn't change, so will point to the new directory (or |
|
|
1189 | nowhere at all), while the directory fd, if available on the system, |
|
|
1190 | will still point to the original directory. Most functions accepting a |
|
|
1191 | pathname will use the directory fd on newer systems, and the string on |
|
|
1192 | older systems. Some functions (such as "aio_realpath") will always rely |
|
|
1193 | on the string form of the pathname. |
|
|
1194 | |
|
|
1195 | So this functionality is mainly useful to get some protection against |
|
|
1196 | "chdir", to easily get an absolute path out of a relative path for |
|
|
1197 | future reference, and to speed up doing many operations in the same |
|
|
1198 | directory (e.g. when stat'ing all files in a directory). |
|
|
1199 | |
|
|
1200 | The following functions implement this working directory abstraction: |
|
|
1201 | |
|
|
1202 | aio_wd $pathname, $callback->($wd) |
|
|
1203 | Asynchonously canonicalise the given pathname and convert it to an |
|
|
1204 | IO::AIO::WD object representing it. If possible and supported on the |
|
|
1205 | system, also open a directory fd to speed up pathname resolution |
|
|
1206 | relative to this working directory. |
|
|
1207 | |
|
|
1208 | If something goes wrong, then "undef" is passwd to the callback |
|
|
1209 | instead of a working directory object and $! is set appropriately. |
|
|
1210 | Since passing "undef" as working directory component of a pathname |
|
|
1211 | fails the request with "ENOENT", there is often no need for error |
|
|
1212 | checking in the "aio_wd" callback, as future requests using the |
|
|
1213 | value will fail in the expected way. |
|
|
1214 | |
|
|
1215 | IO::AIO::CWD |
|
|
1216 | This is a compiletime constant (object) that represents the process |
|
|
1217 | current working directory. |
|
|
1218 | |
|
|
1219 | Specifying this object as working directory object for a pathname is |
|
|
1220 | as if the pathname would be specified directly, without a directory |
|
|
1221 | object. For example, these calls are functionally identical: |
|
|
1222 | |
|
|
1223 | aio_stat "somefile", sub { ... }; |
|
|
1224 | aio_stat [IO::AIO::CWD, "somefile"], sub { ... }; |
|
|
1225 | |
|
|
1226 | To recover the path associated with an IO::AIO::WD object, you can use |
|
|
1227 | "aio_realpath": |
|
|
1228 | |
|
|
1229 | aio_realpath $wd, sub { |
|
|
1230 | warn "path is $_[0]\n"; |
|
|
1231 | }; |
|
|
1232 | |
|
|
1233 | Currently, "aio_statvfs" always, and "aio_rename" and "aio_rmdir" |
|
|
1234 | sometimes, fall back to using an absolue path. |
| 894 | |
1235 | |
| 895 | IO::AIO::REQ CLASS |
1236 | IO::AIO::REQ CLASS |
| 896 | All non-aggregate "aio_*" functions return an object of this class when |
1237 | All non-aggregate "aio_*" functions return an object of this class when |
| 897 | called in non-void context. |
1238 | called in non-void context. |
| 898 | |
1239 | |
| … | |
… | |
| 998 | Sets a feeder/generator on this group: every group can have an |
1339 | Sets a feeder/generator on this group: every group can have an |
| 999 | attached generator that generates requests if idle. The idea behind |
1340 | attached generator that generates requests if idle. The idea behind |
| 1000 | this is that, although you could just queue as many requests as you |
1341 | this is that, although you could just queue as many requests as you |
| 1001 | want in a group, this might starve other requests for a potentially |
1342 | want in a group, this might starve other requests for a potentially |
| 1002 | long time. For example, "aio_scandir" might generate hundreds of |
1343 | long time. For example, "aio_scandir" might generate hundreds of |
| 1003 | thousands "aio_stat" requests, delaying any later requests for a |
1344 | thousands of "aio_stat" requests, delaying any later requests for a |
| 1004 | long time. |
1345 | long time. |
| 1005 | |
1346 | |
| 1006 | To avoid this, and allow incremental generation of requests, you can |
1347 | To avoid this, and allow incremental generation of requests, you can |
| 1007 | instead a group and set a feeder on it that generates those |
1348 | instead a group and set a feeder on it that generates those |
| 1008 | requests. The feed callback will be called whenever there are few |
1349 | requests. The feed callback will be called whenever there are few |
| … | |
… | |
| 1050 | results. |
1391 | results. |
| 1051 | |
1392 | |
| 1052 | See "poll_cb" for an example. |
1393 | See "poll_cb" for an example. |
| 1053 | |
1394 | |
| 1054 | IO::AIO::poll_cb |
1395 | IO::AIO::poll_cb |
| 1055 | Process some outstanding events on the result pipe. You have to call |
1396 | Process some requests that have reached the result phase (i.e. they |
|
|
1397 | have been executed but the results are not yet reported). You have |
|
|
1398 | to call this "regularly" to finish outstanding requests. |
|
|
1399 | |
| 1056 | this regularly. Returns 0 if all events could be processed (or there |
1400 | Returns 0 if all events could be processed (or there were no events |
| 1057 | were no events to process), or -1 if it returned earlier for |
1401 | to process), or -1 if it returned earlier for whatever reason. |
| 1058 | whatever reason. Returns immediately when no events are outstanding. |
1402 | Returns immediately when no events are outstanding. The amount of |
| 1059 | The amount of events processed depends on the settings of |
1403 | events processed depends on the settings of "IO::AIO::max_poll_req", |
| 1060 | "IO::AIO::max_poll_req" and "IO::AIO::max_poll_time". |
1404 | "IO::AIO::max_poll_time" and "IO::AIO::max_outstanding". |
| 1061 | |
1405 | |
| 1062 | If not all requests were processed for whatever reason, the |
1406 | If not all requests were processed for whatever reason, the poll |
| 1063 | filehandle will still be ready when "poll_cb" returns, so normally |
1407 | file descriptor will still be ready when "poll_cb" returns, so |
| 1064 | you don't have to do anything special to have it called later. |
1408 | normally you don't have to do anything special to have it called |
|
|
1409 | later. |
| 1065 | |
1410 | |
| 1066 | Apart from calling "IO::AIO::poll_cb" when the event filehandle |
1411 | Apart from calling "IO::AIO::poll_cb" when the event filehandle |
| 1067 | becomes ready, it can be beneficial to call this function from loops |
1412 | becomes ready, it can be beneficial to call this function from loops |
| 1068 | which submit a lot of requests, to make sure the results get |
1413 | which submit a lot of requests, to make sure the results get |
| 1069 | processed when they become available and not just when the loop is |
1414 | processed when they become available and not just when the loop is |
| … | |
… | |
| 1077 | Event->io (fd => IO::AIO::poll_fileno, |
1422 | Event->io (fd => IO::AIO::poll_fileno, |
| 1078 | poll => 'r', async => 1, |
1423 | poll => 'r', async => 1, |
| 1079 | cb => \&IO::AIO::poll_cb); |
1424 | cb => \&IO::AIO::poll_cb); |
| 1080 | |
1425 | |
| 1081 | IO::AIO::poll_wait |
1426 | IO::AIO::poll_wait |
| 1082 | If there are any outstanding requests and none of them in the result |
1427 | Wait until either at least one request is in the result phase or no |
| 1083 | phase, wait till the result filehandle becomes ready for reading |
1428 | requests are outstanding anymore. |
| 1084 | (simply does a "select" on the filehandle. This is useful if you |
1429 | |
| 1085 | want to synchronously wait for some requests to finish). |
1430 | This is useful if you want to synchronously wait for some requests |
|
|
1431 | to become ready, without actually handling them. |
| 1086 | |
1432 | |
| 1087 | See "nreqs" for an example. |
1433 | See "nreqs" for an example. |
| 1088 | |
1434 | |
| 1089 | IO::AIO::poll |
1435 | IO::AIO::poll |
| 1090 | Waits until some requests have been handled. |
1436 | Waits until some requests have been handled. |
| … | |
… | |
| 1202 | |
1548 | |
| 1203 | This is a very bad function to use in interactive programs because |
1549 | This is a very bad function to use in interactive programs because |
| 1204 | it blocks, and a bad way to reduce concurrency because it is |
1550 | it blocks, and a bad way to reduce concurrency because it is |
| 1205 | inexact: Better use an "aio_group" together with a feed callback. |
1551 | inexact: Better use an "aio_group" together with a feed callback. |
| 1206 | |
1552 | |
| 1207 | It's main use is in scripts without an event loop - when you want to |
1553 | Its main use is in scripts without an event loop - when you want to |
| 1208 | stat a lot of files, you can write somehting like this: |
1554 | stat a lot of files, you can write something like this: |
| 1209 | |
1555 | |
| 1210 | IO::AIO::max_outstanding 32; |
1556 | IO::AIO::max_outstanding 32; |
| 1211 | |
1557 | |
| 1212 | for my $path (...) { |
1558 | for my $path (...) { |
| 1213 | aio_stat $path , ...; |
1559 | aio_stat $path , ...; |
| … | |
… | |
| 1243 | IO::AIO::npending |
1589 | IO::AIO::npending |
| 1244 | Returns the number of requests currently in the pending state |
1590 | Returns the number of requests currently in the pending state |
| 1245 | (executed, but not yet processed by poll_cb). |
1591 | (executed, but not yet processed by poll_cb). |
| 1246 | |
1592 | |
| 1247 | MISCELLANEOUS FUNCTIONS |
1593 | MISCELLANEOUS FUNCTIONS |
| 1248 | IO::AIO implements some functions that might be useful, but are not |
1594 | IO::AIO implements some functions that are useful when you want to use |
| 1249 | asynchronous. |
1595 | some "Advanced I/O" function not available to in Perl, without going the |
|
|
1596 | "Asynchronous I/O" route. Many of these have an asynchronous "aio_*" |
|
|
1597 | counterpart. |
|
|
1598 | |
|
|
1599 | $numfd = IO::AIO::get_fdlimit |
|
|
1600 | This function is *EXPERIMENTAL* and subject to change. |
|
|
1601 | |
|
|
1602 | Tries to find the current file descriptor limit and returns it, or |
|
|
1603 | "undef" and sets $! in case of an error. The limit is one larger |
|
|
1604 | than the highest valid file descriptor number. |
|
|
1605 | |
|
|
1606 | IO::AIO::min_fdlimit [$numfd] |
|
|
1607 | This function is *EXPERIMENTAL* and subject to change. |
|
|
1608 | |
|
|
1609 | Try to increase the current file descriptor limit(s) to at least |
|
|
1610 | $numfd by changing the soft or hard file descriptor resource limit. |
|
|
1611 | If $numfd is missing, it will try to set a very high limit, although |
|
|
1612 | this is not recommended when you know the actual minimum that you |
|
|
1613 | require. |
|
|
1614 | |
|
|
1615 | If the limit cannot be raised enough, the function makes a |
|
|
1616 | best-effort attempt to increase the limit as much as possible, using |
|
|
1617 | various tricks, while still failing. You can query the resulting |
|
|
1618 | limit using "IO::AIO::get_fdlimit". |
|
|
1619 | |
|
|
1620 | If an error occurs, returns "undef" and sets $!, otherwise returns |
|
|
1621 | true. |
| 1250 | |
1622 | |
| 1251 | IO::AIO::sendfile $ofh, $ifh, $offset, $count |
1623 | IO::AIO::sendfile $ofh, $ifh, $offset, $count |
| 1252 | Calls the "eio_sendfile_sync" function, which is like |
1624 | Calls the "eio_sendfile_sync" function, which is like |
| 1253 | "aio_sendfile", but is blocking (this makes most sense if you know |
1625 | "aio_sendfile", but is blocking (this makes most sense if you know |
| 1254 | the input data is likely cached already and the output filehandle is |
1626 | the input data is likely cached already and the output filehandle is |
| … | |
… | |
| 1256 | |
1628 | |
| 1257 | Returns the number of bytes copied, or -1 on error. |
1629 | Returns the number of bytes copied, or -1 on error. |
| 1258 | |
1630 | |
| 1259 | IO::AIO::fadvise $fh, $offset, $len, $advice |
1631 | IO::AIO::fadvise $fh, $offset, $len, $advice |
| 1260 | Simply calls the "posix_fadvise" function (see its manpage for |
1632 | Simply calls the "posix_fadvise" function (see its manpage for |
| 1261 | details). The following advice constants are avaiable: |
1633 | details). The following advice constants are available: |
| 1262 | "IO::AIO::FADV_NORMAL", "IO::AIO::FADV_SEQUENTIAL", |
1634 | "IO::AIO::FADV_NORMAL", "IO::AIO::FADV_SEQUENTIAL", |
| 1263 | "IO::AIO::FADV_RANDOM", "IO::AIO::FADV_NOREUSE", |
1635 | "IO::AIO::FADV_RANDOM", "IO::AIO::FADV_NOREUSE", |
| 1264 | "IO::AIO::FADV_WILLNEED", "IO::AIO::FADV_DONTNEED". |
1636 | "IO::AIO::FADV_WILLNEED", "IO::AIO::FADV_DONTNEED". |
| 1265 | |
1637 | |
| 1266 | On systems that do not implement "posix_fadvise", this function |
1638 | On systems that do not implement "posix_fadvise", this function |
| 1267 | returns ENOSYS, otherwise the return value of "posix_fadvise". |
1639 | returns ENOSYS, otherwise the return value of "posix_fadvise". |
| 1268 | |
1640 | |
| 1269 | IO::AIO::madvise $scalar, $offset, $len, $advice |
1641 | IO::AIO::madvise $scalar, $offset, $len, $advice |
| 1270 | Simply calls the "posix_madvise" function (see its manpage for |
1642 | Simply calls the "posix_madvise" function (see its manpage for |
| 1271 | details). The following advice constants are avaiable: |
1643 | details). The following advice constants are available: |
| 1272 | "IO::AIO::MADV_NORMAL", "IO::AIO::MADV_SEQUENTIAL", |
1644 | "IO::AIO::MADV_NORMAL", "IO::AIO::MADV_SEQUENTIAL", |
| 1273 | "IO::AIO::MADV_RANDOM", "IO::AIO::MADV_WILLNEED", |
1645 | "IO::AIO::MADV_RANDOM", "IO::AIO::MADV_WILLNEED", |
| 1274 | "IO::AIO::MADV_DONTNEED". |
1646 | "IO::AIO::MADV_DONTNEED". |
| 1275 | |
1647 | |
|
|
1648 | If $offset is negative, counts from the end. If $length is negative, |
|
|
1649 | the remaining length of the $scalar is used. If possible, $length |
|
|
1650 | will be reduced to fit into the $scalar. |
|
|
1651 | |
| 1276 | On systems that do not implement "posix_madvise", this function |
1652 | On systems that do not implement "posix_madvise", this function |
| 1277 | returns ENOSYS, otherwise the return value of "posix_madvise". |
1653 | returns ENOSYS, otherwise the return value of "posix_madvise". |
| 1278 | |
1654 | |
| 1279 | IO::AIO::mprotect $scalar, $offset, $len, $protect |
1655 | IO::AIO::mprotect $scalar, $offset, $len, $protect |
| 1280 | Simply calls the "mprotect" function on the preferably AIO::mmap'ed |
1656 | Simply calls the "mprotect" function on the preferably AIO::mmap'ed |
| 1281 | $scalar (see its manpage for details). The following protect |
1657 | $scalar (see its manpage for details). The following protect |
| 1282 | constants are avaiable: "IO::AIO::PROT_NONE", "IO::AIO::PROT_READ", |
1658 | constants are available: "IO::AIO::PROT_NONE", "IO::AIO::PROT_READ", |
| 1283 | "IO::AIO::PROT_WRITE", "IO::AIO::PROT_EXEC". |
1659 | "IO::AIO::PROT_WRITE", "IO::AIO::PROT_EXEC". |
|
|
1660 | |
|
|
1661 | If $offset is negative, counts from the end. If $length is negative, |
|
|
1662 | the remaining length of the $scalar is used. If possible, $length |
|
|
1663 | will be reduced to fit into the $scalar. |
| 1284 | |
1664 | |
| 1285 | On systems that do not implement "mprotect", this function returns |
1665 | On systems that do not implement "mprotect", this function returns |
| 1286 | ENOSYS, otherwise the return value of "mprotect". |
1666 | ENOSYS, otherwise the return value of "mprotect". |
| 1287 | |
1667 | |
| 1288 | IO::AIO::mmap $scalar, $length, $prot, $flags, $fh[, $offset] |
1668 | IO::AIO::mmap $scalar, $length, $prot, $flags, $fh[, $offset] |
| 1289 | Memory-maps a file (or anonymous memory range) and attaches it to |
1669 | Memory-maps a file (or anonymous memory range) and attaches it to |
| 1290 | the given $scalar, which will act like a string scalar. |
1670 | the given $scalar, which will act like a string scalar. Returns true |
|
|
1671 | on success, and false otherwise. |
| 1291 | |
1672 | |
|
|
1673 | The scalar must exist, but its contents do not matter - this means |
|
|
1674 | you cannot use a nonexistant array or hash element. When in doubt, |
|
|
1675 | "undef" the scalar first. |
|
|
1676 | |
| 1292 | The only operations allowed on the scalar are "substr"/"vec" that |
1677 | The only operations allowed on the mmapped scalar are |
| 1293 | don't change the string length, and most read-only operations such |
1678 | "substr"/"vec", which don't change the string length, and most |
| 1294 | as copying it or searching it with regexes and so on. |
1679 | read-only operations such as copying it or searching it with regexes |
|
|
1680 | and so on. |
| 1295 | |
1681 | |
| 1296 | Anything else is unsafe and will, at best, result in memory leaks. |
1682 | Anything else is unsafe and will, at best, result in memory leaks. |
| 1297 | |
1683 | |
| 1298 | The memory map associated with the $scalar is automatically removed |
1684 | The memory map associated with the $scalar is automatically removed |
| 1299 | when the $scalar is destroyed, or when the "IO::AIO::mmap" or |
1685 | when the $scalar is undef'd or destroyed, or when the |
| 1300 | "IO::AIO::munmap" functions are called. |
1686 | "IO::AIO::mmap" or "IO::AIO::munmap" functions are called on it. |
| 1301 | |
1687 | |
| 1302 | This calls the "mmap"(2) function internally. See your system's |
1688 | This calls the "mmap"(2) function internally. See your system's |
| 1303 | manual page for details on the $length, $prot and $flags parameters. |
1689 | manual page for details on the $length, $prot and $flags parameters. |
| 1304 | |
1690 | |
| 1305 | The $length must be larger than zero and smaller than the actual |
1691 | The $length must be larger than zero and smaller than the actual |
| … | |
… | |
| 1309 | "IO::AIO::PROT_EXEC", "IO::AIO::PROT_READ" and/or |
1695 | "IO::AIO::PROT_EXEC", "IO::AIO::PROT_READ" and/or |
| 1310 | "IO::AIO::PROT_WRITE", |
1696 | "IO::AIO::PROT_WRITE", |
| 1311 | |
1697 | |
| 1312 | $flags can be a combination of "IO::AIO::MAP_SHARED" or |
1698 | $flags can be a combination of "IO::AIO::MAP_SHARED" or |
| 1313 | "IO::AIO::MAP_PRIVATE", or a number of system-specific flags (when |
1699 | "IO::AIO::MAP_PRIVATE", or a number of system-specific flags (when |
| 1314 | not available, the are defined as 0): "IO::AIO::MAP_ANONYMOUS" |
1700 | not available, the are 0): "IO::AIO::MAP_ANONYMOUS" (which is set to |
| 1315 | (which is set to "MAP_ANON" if your system only provides this |
1701 | "MAP_ANON" if your system only provides this constant), |
|
|
1702 | "IO::AIO::MAP_LOCKED", "IO::AIO::MAP_NORESERVE", |
| 1316 | constant), "IO::AIO::MAP_HUGETLB", "IO::AIO::MAP_LOCKED", |
1703 | "IO::AIO::MAP_POPULATE", "IO::AIO::MAP_NONBLOCK", |
|
|
1704 | "IO::AIO::MAP_FIXED", "IO::AIO::MAP_GROWSDOWN", |
| 1317 | "IO::AIO::MAP_NORESERVE", "IO::AIO::MAP_POPULATE" or |
1705 | "IO::AIO::MAP_32BIT", "IO::AIO::MAP_HUGETLB" or |
| 1318 | "IO::AIO::MAP_NONBLOCK" |
1706 | "IO::AIO::MAP_STACK". |
| 1319 | |
1707 | |
| 1320 | If $fh is "undef", then a file descriptor of -1 is passed. |
1708 | If $fh is "undef", then a file descriptor of -1 is passed. |
| 1321 | |
1709 | |
| 1322 | $offset is the offset from the start of the file - it generally must |
1710 | $offset is the offset from the start of the file - it generally must |
| 1323 | be a multiple of "IO::AIO::PAGESIZE" and defaults to 0. |
1711 | be a multiple of "IO::AIO::PAGESIZE" and defaults to 0. |
| … | |
… | |
| 1345 | IO::AIO::munlockall |
1733 | IO::AIO::munlockall |
| 1346 | Calls the "munlockall" function. |
1734 | Calls the "munlockall" function. |
| 1347 | |
1735 | |
| 1348 | On systems that do not implement "munlockall", this function returns |
1736 | On systems that do not implement "munlockall", this function returns |
| 1349 | ENOSYS, otherwise the return value of "munlockall". |
1737 | ENOSYS, otherwise the return value of "munlockall". |
|
|
1738 | |
|
|
1739 | IO::AIO::splice $r_fh, $r_off, $w_fh, $w_off, $length, $flags |
|
|
1740 | Calls the GNU/Linux splice(2) syscall, if available. If $r_off or |
|
|
1741 | $w_off are "undef", then "NULL" is passed for these, otherwise they |
|
|
1742 | should be the file offset. |
|
|
1743 | |
|
|
1744 | $r_fh and $w_fh should not refer to the same file, as splice might |
|
|
1745 | silently corrupt the data in this case. |
|
|
1746 | |
|
|
1747 | The following symbol flag values are available: |
|
|
1748 | "IO::AIO::SPLICE_F_MOVE", "IO::AIO::SPLICE_F_NONBLOCK", |
|
|
1749 | "IO::AIO::SPLICE_F_MORE" and "IO::AIO::SPLICE_F_GIFT". |
|
|
1750 | |
|
|
1751 | See the splice(2) manpage for details. |
|
|
1752 | |
|
|
1753 | IO::AIO::tee $r_fh, $w_fh, $length, $flags |
|
|
1754 | Calls the GNU/Linux tee(2) syscall, see its manpage and the |
|
|
1755 | description for "IO::AIO::splice" above for details. |
|
|
1756 | |
|
|
1757 | $actual_size = IO::AIO::pipesize $r_fh[, $new_size] |
|
|
1758 | Attempts to query or change the pipe buffer size. Obviously works |
|
|
1759 | only on pipes, and currently works only on GNU/Linux systems, and |
|
|
1760 | fails with -1/"ENOSYS" everywhere else. If anybody knows how to |
|
|
1761 | influence pipe buffer size on other systems, drop me a note. |
|
|
1762 | |
|
|
1763 | ($rfh, $wfh) = IO::AIO::pipe2 [$flags] |
|
|
1764 | This is a direct interface to the Linux pipe2(2) system call. If |
|
|
1765 | $flags is missing or 0, then this should be the same as a call to |
|
|
1766 | perl's built-in "pipe" function and create a new pipe, and works on |
|
|
1767 | systems that lack the pipe2 syscall. On win32, this case invokes |
|
|
1768 | "_pipe (..., 4096, O_BINARY)". |
|
|
1769 | |
|
|
1770 | If $flags is non-zero, it tries to invoke the pipe2 system call with |
|
|
1771 | the given flags (Linux 2.6.27, glibc 2.9). |
|
|
1772 | |
|
|
1773 | On success, the read and write file handles are returned. |
|
|
1774 | |
|
|
1775 | On error, nothing will be returned. If the pipe2 syscall is missing |
|
|
1776 | and $flags is non-zero, fails with "ENOSYS". |
|
|
1777 | |
|
|
1778 | Please refer to pipe2(2) for more info on the $flags, but at the |
|
|
1779 | time of this writing, "IO::AIO::O_CLOEXEC", "IO::AIO::O_NONBLOCK" |
|
|
1780 | and "IO::AIO::O_DIRECT" (Linux 3.4, for packet-based pipes) were |
|
|
1781 | supported. |
|
|
1782 | |
|
|
1783 | Example: create a pipe race-free w.r.t. threads and fork: |
|
|
1784 | |
|
|
1785 | my ($rfh, $wfh) = IO::AIO::pipe2 IO::AIO::O_CLOEXEC |
|
|
1786 | or die "pipe2: $!\n"; |
|
|
1787 | |
|
|
1788 | $fh = IO::AIO::eventfd [$initval, [$flags]] |
|
|
1789 | This is a direct interface to the Linux eventfd(2) system call. The |
|
|
1790 | (unhelpful) defaults for $initval and $flags are 0 for both. |
|
|
1791 | |
|
|
1792 | On success, the new eventfd filehandle is returned, otherwise |
|
|
1793 | returns "undef". If the eventfd syscall is missing, fails with |
|
|
1794 | "ENOSYS". |
|
|
1795 | |
|
|
1796 | Please refer to eventfd(2) for more info on this call. |
|
|
1797 | |
|
|
1798 | The following symbol flag values are available: |
|
|
1799 | "IO::AIO::EFD_CLOEXEC", "IO::AIO::EFD_NONBLOCK" and |
|
|
1800 | "IO::AIO::EFD_SEMAPHORE" (Linux 2.6.30). |
|
|
1801 | |
|
|
1802 | Example: create a new eventfd filehandle: |
|
|
1803 | |
|
|
1804 | $fh = IO::AIO::eventfd 0, IO::AIO::O_CLOEXEC |
|
|
1805 | or die "eventfd: $!\n"; |
|
|
1806 | |
|
|
1807 | $fh = IO::AIO::timerfd_create $clockid[, $flags] |
|
|
1808 | This is a direct interface to the Linux timerfd_create(2) system |
|
|
1809 | call. The (unhelpful) default for $flags is 0. |
|
|
1810 | |
|
|
1811 | On success, the new timerfd filehandle is returned, otherwise |
|
|
1812 | returns "undef". If the eventfd syscall is missing, fails with |
|
|
1813 | "ENOSYS". |
|
|
1814 | |
|
|
1815 | Please refer to timerfd_create(2) for more info on this call. |
|
|
1816 | |
|
|
1817 | The following $clockid values are available: |
|
|
1818 | "IO::AIO::CLOCK_REALTIME", "IO::AIO::CLOCK_MONOTONIC" |
|
|
1819 | "IO::AIO::CLOCK_CLOCK_BOOTTIME" (Linux 3.15) |
|
|
1820 | "IO::AIO::CLOCK_CLOCK_REALTIME_ALARM" (Linux 3.11) and |
|
|
1821 | "IO::AIO::CLOCK_CLOCK_BOOTTIME_ALARM" (Linux 3.11). |
|
|
1822 | |
|
|
1823 | The following $flags values are available (Linux 2.6.27): |
|
|
1824 | "IO::AIO::TFD_NONBLOCK" and "IO::AIO::TFD_CLOEXEC". |
|
|
1825 | |
|
|
1826 | Example: create a new timerfd and set it to one-second repeated |
|
|
1827 | alarms, then wait for two alarms: |
|
|
1828 | |
|
|
1829 | my $fh = IO::AIO::timerfd_create IO::AIO::CLOCK_BOOTTIME, IO::AIO::TFD_CLOEXEC |
|
|
1830 | or die "timerfd_create: $!\n"; |
|
|
1831 | |
|
|
1832 | defined IO::AIO::timerfd_settime $fh, 0, 1, 1 |
|
|
1833 | or die "timerfd_settime: $!\n"; |
|
|
1834 | |
|
|
1835 | for (1..2) { |
|
|
1836 | 8 == sysread $fh, my $buf, 8 |
|
|
1837 | or die "timerfd read failure\n"; |
|
|
1838 | |
|
|
1839 | printf "number of expirations (likely 1): %d\n", |
|
|
1840 | unpack "Q", $buf; |
|
|
1841 | } |
|
|
1842 | |
|
|
1843 | ($cur_interval, $cur_value) = IO::AIO::timerfd_settime $fh, $flags, |
|
|
1844 | $new_interval, $nbw_value |
|
|
1845 | This is a direct interface to the Linux timerfd_settime(2) system |
|
|
1846 | call. Please refer to its manpage for more info on this call. |
|
|
1847 | |
|
|
1848 | The new itimerspec is specified using two (possibly fractional) |
|
|
1849 | second values, $new_interval and $new_value). |
|
|
1850 | |
|
|
1851 | On success, the current interval and value are returned (as per |
|
|
1852 | "timerfd_gettime"). On failure, the empty list is returned. |
|
|
1853 | |
|
|
1854 | The following $flags values are available: |
|
|
1855 | "IO::AIO::TFD_TIMER_ABSTIME" and "IO::AIO::TFD_TIMER_CANCEL_ON_SET". |
|
|
1856 | |
|
|
1857 | See "IO::AIO::timerfd_create" for a full example. |
|
|
1858 | |
|
|
1859 | ($cur_interval, $cur_value) = IO::AIO::timerfd_gettime $fh |
|
|
1860 | This is a direct interface to the Linux timerfd_gettime(2) system |
|
|
1861 | call. Please refer to its manpage for more info on this call. |
|
|
1862 | |
|
|
1863 | On success, returns the current values of interval and value for the |
|
|
1864 | given timerfd (as potentially fractional second values). On failure, |
|
|
1865 | the empty list is returned. |
| 1350 | |
1866 | |
| 1351 | EVENT LOOP INTEGRATION |
1867 | EVENT LOOP INTEGRATION |
| 1352 | It is recommended to use AnyEvent::AIO to integrate IO::AIO |
1868 | It is recommended to use AnyEvent::AIO to integrate IO::AIO |
| 1353 | automatically into many event loops: |
1869 | automatically into many event loops: |
| 1354 | |
1870 | |
| … | |
… | |
| 1393 | |
1909 | |
| 1394 | You might get around by not *using* IO::AIO before (or after) forking. |
1910 | You might get around by not *using* IO::AIO before (or after) forking. |
| 1395 | You could also try to call the IO::AIO::reinit function in the child: |
1911 | You could also try to call the IO::AIO::reinit function in the child: |
| 1396 | |
1912 | |
| 1397 | IO::AIO::reinit |
1913 | IO::AIO::reinit |
| 1398 | Abondons all current requests and I/O threads and simply |
1914 | Abandons all current requests and I/O threads and simply |
| 1399 | reinitialises all data structures. This is not an operation |
1915 | reinitialises all data structures. This is not an operation |
| 1400 | suppported by any standards, but happens to work on GNU/Linux and |
1916 | supported by any standards, but happens to work on GNU/Linux and |
| 1401 | some newer BSD systems. |
1917 | some newer BSD systems. |
| 1402 | |
1918 | |
| 1403 | The only reasonable use for this function is to call it after |
1919 | The only reasonable use for this function is to call it after |
| 1404 | forking, if "IO::AIO" was used in the parent. Calling it while |
1920 | forking, if "IO::AIO" was used in the parent. Calling it while |
| 1405 | IO::AIO is active in the process will result in undefined behaviour. |
1921 | IO::AIO is active in the process will result in undefined behaviour. |
| 1406 | Calling it at any time will also result in any undefined (by POSIX) |
1922 | Calling it at any time will also result in any undefined (by POSIX) |
| 1407 | behaviour. |
1923 | behaviour. |
| 1408 | |
1924 | |
|
|
1925 | LINUX-SPECIFIC CALLS |
|
|
1926 | When a call is documented as "linux-specific" then this means it |
|
|
1927 | originated on GNU/Linux. "IO::AIO" will usually try to autodetect the |
|
|
1928 | availability and compatibility of such calls regardless of the platform |
|
|
1929 | it is compiled on, so platforms such as FreeBSD which often implement |
|
|
1930 | these calls will work. When in doubt, call them and see if they fail wth |
|
|
1931 | "ENOSYS". |
|
|
1932 | |
| 1409 | MEMORY USAGE |
1933 | MEMORY USAGE |
| 1410 | Per-request usage: |
1934 | Per-request usage: |
| 1411 | |
1935 | |
| 1412 | Each aio request uses - depending on your architecture - around 100-200 |
1936 | Each aio request uses - depending on your architecture - around 100-200 |
| 1413 | bytes of memory. In addition, stat requests need a stat buffer (possibly |
1937 | bytes of memory. In addition, stat requests need a stat buffer (possibly |
| … | |
… | |
| 1423 | In the execution phase, some aio requests require more memory for |
1947 | In the execution phase, some aio requests require more memory for |
| 1424 | temporary buffers, and each thread requires a stack and other data |
1948 | temporary buffers, and each thread requires a stack and other data |
| 1425 | structures (usually around 16k-128k, depending on the OS). |
1949 | structures (usually around 16k-128k, depending on the OS). |
| 1426 | |
1950 | |
| 1427 | KNOWN BUGS |
1951 | KNOWN BUGS |
| 1428 | Known bugs will be fixed in the next release. |
1952 | Known bugs will be fixed in the next release :) |
|
|
1953 | |
|
|
1954 | KNOWN ISSUES |
|
|
1955 | Calls that try to "import" foreign memory areas (such as "IO::AIO::mmap" |
|
|
1956 | or "IO::AIO::aio_slurp") do not work with generic lvalues, such as |
|
|
1957 | non-created hash slots or other scalars I didn't think of. It's best to |
|
|
1958 | avoid such and either use scalar variables or making sure that the |
|
|
1959 | scalar exists (e.g. by storing "undef") and isn't "funny" (e.g. tied). |
|
|
1960 | |
|
|
1961 | I am not sure anything can be done about this, so this is considered a |
|
|
1962 | known issue, rather than a bug. |
| 1429 | |
1963 | |
| 1430 | SEE ALSO |
1964 | SEE ALSO |
| 1431 | AnyEvent::AIO for easy integration into event loops, Coro::AIO for a |
1965 | AnyEvent::AIO for easy integration into event loops, Coro::AIO for a |
| 1432 | more natural syntax. |
1966 | more natural syntax. |
| 1433 | |
1967 | |
